Suction cleaner



,July 3o, 1940. y C, H, TAYLQR 2,209,799-

SUCTION CLEANER` Filed July 2:5, 195s EE u r. i l 4 INYEN-ron Il Charles JZ @lop 'krTcRNEY Patented July 30, 1940 PATENT o FFICE sUCTIoN CLEANER Charles H. Taylor,

corporation of Chio Springfield, Mass., assignor to The Hoover Company,

North Canton, Ohio, a

Application July z3, 193s, serial No. 220,916

l Claims. This invention relates to improvements in suction cleaners and more particularly to meansA for maintaining the nozzle of a suction cleaner at a substantially constant height relative to the surface of the floor covering to be cleaned regardless of its quality, texture or other characteristics.

Heretofore, it has been the standard practice to equip suction cleaners with some' form of manually operated mechanism or device for adjusting the height of the nozzle for different grades and thickness of carpet, together with visual indicators to tell the operator whether the nozzle is set at the loW, medium, or high position. But notwithstanding the means available for making the nozzle adjustment, it is very likely to `be incorrectly performed, if not-neg-l lectedentirely, due to lack of knowledge of the proper procedure on the part of the user. Obviously then, the solution of the problem is to eliminate the uncertain and haphazard aspects of nozzle height adjustment by incorporating an arrangement whereby the nozzle will be automatically adjusted to the particular kind or texture of carpet to be cleaned and thus eliminate the necessity for relying upon the operator to perform any act other than operating the vcleaner in the usual manner.

It is therefore the object of the present invention to provide a suction cleaner so designed as to distribute the`weight'and` operating load in such a manner as t'o insure a substantiallyuniform nozzle height regardless of the character or texture of the particular carpet being cleaned.

With the foregoing introductory matter, the invention will now be nection with the accompanying drawing in which:

Figure 1 is a view in side elevation of asucti'on cleaner embodying the novel type of nozzle adjusting mechanism;

Figure 2 is a fragmentary vbottom plan view showing the mounting of the adjusting wheels;

Figure 3 is a detail View in on line 3-3 of Figure 1;

Figure 4 is a fragmentary view in side elevation of a modified arrangement of the front supporting wheels; and

Figure 5 is a view in line 5 5 of Figure 4. t

The suction cleaner herein disclosed may be representative of any standard -handled-maneuvered device consisting generally of a casing I, provided with a nozzle portion 2 extending transvertical section taken on versely across its forward end and supported upon wheels preferably mounted adjacent its front and rear ends. vAhandle 3 is pivotally more fully disclosed ln convertical section taken mounted on the cleaner in such a way as to swing freely about a horizontaltransverse axis in ma# neuvering the cleaner over the carpet surface. 'Ihe cleaner casing I includes a fan chamber in which is located a motor-driven fan, the fan chamber communicating with the nozzlethrough an air in-take passage and also with a dirt bag or receptacle through a suitable discharge passage. These and other operative features of the cleaner are standard, and described in detail. i

As previously mentioned, the cleaner casing is supported upon wheels, the rear wheels 4, `4, preferably included in a caster assembly permanently fixed to the underside of the cleaner casing adja- 15 cent its rear end. 'Ihe front wheels consist of two pairs 5, 5 and 6', .6, one wheel of each pair being combined to form a set located within downwardly facing cavities at opposite ends of the nozzlel portion 2 of the cleaner. casing, these cavities being elongated in a forward and rearwardly direction and relatively narrow in a transverse direction.

Referring now to the front wheel mountings, each set consists of a leading wheel and a trailing wheel 5 arranged in tandem and journalled at the opposite ends of a horizontal rocker bar 1, which in turn has pivotal connection with the cleaner casing at a point intermediate its ends and preferably nearer the axis of the rear wheel than that of the front wheel.. As clearly shown .in Figure 2, the wheels-revolve on journal pins 8 projecting inwardly at right angles from the ends of the bar and the `bar is mounted on a stubshaft 9 projecting from-'the inner face of the end 35 wall of the nozzle casing and providing a simple form of bearing on Vwhich the bar l is free t0 rock.-v l 'I'he sets of tandemearranged front wheels 5 and 6 at each `side of the'casing are preferably of Athe same standard size and dimensions,. although it would be quite practical to use wheels of varying dimensions-as for example by utilizing rela-lv tively wide front wheels in order' to afford greater resistance to penetration into the carpet nap. Similarly, the length of the wheel supporting bar "I, the distance of Vits. pivot pointfrom each end and its relation to the center of massI of the'cleaner may likewise be variedr for different types and models of cleaners. However, the factors to be taken into consideration'in the application of the automatic adjustment to a given cleaner, will now be discussed in detail: Y t In the rst place, it will be observed that the -handle 3 is pivotally mounted well towards the rear of the cleaner casing I,` in fact, the pivot 55 therefore need not be 10 into operation, it follows point of the handle may be assumed to lie approximately in vertical alignment with the aids of the rear wheels 4. With this arrangement, the center of mass of the cleaner will fall somewhere between the front and rear wheels, therefore the static load will be fairly evenly distributed therebetween.

This condition however, exists only in the nonoperating condition of the cleaner, for obviously upon starting the cleaner the suction acting at the nozzle is an additional load and may be considered as acting in a downward direction at the center of the nozzle. And finally, to propel the cleaner over the surface of the carpet, force is applied thro'gh the handle-arid acting at its point of attachment with the cleaner body and at different angles depending on'the position of the handle. Moreover, if the force exerted through the handle be resolved into its horizontal and vertical components, the horizontal component is effective to propel the cleaner body Whereas the vertical component is distributed between the front and rear wheels as a varying vertical load.

But it is to be noted that since the cleaner handle is attached to the body at a point substantially above the rear wheels, the greater part of the vertical load, that is, the vertical component of the force exerted to the handle is carried by the rear wheels 4, thus leaving the front wheels 5 and 6 comparatively free to support the weight of the cleaner body or static load and the suction load, unaffected by the force exerted through the handle.

Thus it follows lthat regardless of the grade or texture of carpet being cleaned, there will be a substantial penetration of the carpet nap by the rear wheels 4, as clearly shown in Figure l, but owing to the relatively large supporting surface offered by the front wheels 5 and 6, the latter will ride on top of the carpet nap and with relatively less penetration. And, since the height of the nozzle above the carpet surface iS- determined by the vertical disposition of the front wheels 5 and 6 relative thereto, it maintains a constant height in the same degree as the front wheels 5 and 6 resist sinking into the carpet nap under the load carried thereby.

As a practical matter however, there will be some penetration of the front wheels 5 and 5 regardless of their dimensions or area of tread surface in contact with-the carpet. And con. sequently, it is the purpose of the particular tan? dem arrangement of the pairs of front wheels 5 a'fi'd 6 to clnpensafor the "appreciable, though relatively less depth of pile penetration. To explain further: If the cleaner be placed upon a carpet of medium thickness without being put that the static load will be distributed fairly uniformly between the several supporting wheels and that all will penetrate the carpet nap to substantially the same depth, as shown by the full line position of the leading wheels 5 and the dotted line position of the trailing front wheels 5 and the rear supporting wheels l. Now, assuming that the cleaner is started and the suction load applied, thix will immediateLv result in an increased load upon each pair of front wheels 5 and 5, but since these wheels are journalled at opposite ends of the rocker bar 1 and the latter is pivotally connected to the cleaner body at a point nearer the axis of the trailing wheels 5, it follows that the load on the tandem front wheels will be distributed inversely as the length of their lever arms and therefore the trailing wheels assuming the greater part of the load, tend to sink into the carpet nap in consequence thereof, the leading wheels '6 will continue to rest more nearly on top of the carpet pile with their axes forming relatively stationary fulcrums about which the forward portion of the cleaner body rocks and this movement compensates for the penetration of the trailing wheels 5, 5 by decreasing the vertical displacement of the wheel supporting studs 9 which actually determines the height of the noz.- zle above the surface of the carpet.

It will be observed also that while the vertical adjustment of the nozzle may be actually less than the depth of wheel penetration, there is a further compensating factor to be taken into consideration, namely, a denite tilting of the forward portion of the cleaner body upwardly as the rear Wheels sink into the nap due to the forces exerted downwardly through the handle y in maneuvering the cleaner forwardly over the carpet. Thus, the net result is a close approximation to a condition of constant or uniform nozzle height, which is obtained regardless of the kind or character of the carpet on which the cleaner is being operated.

A practical modification of the adjustment just described is disclosed in Figures 4 and 5, wherein a similar arrangement of tandem wheels is employed, but in this instance each pair of wheels Ill and II is journalled, one behind the other, intermediate the ends of a frame I2, consisting of a U-shaped bar having pivotal connection at its forward end with a bracket I3 fixed to the vertical rear wall I4 of the nozzle chamber and resiliently supported by a compression spring positioned between its upturned rear end I2a and the underside of the casing I.

In this modified tandemarrangement of front supporting wheels (duplicated on both sides of the cleaner body) the compression springs l5, I5 are just strong enough to support the normal static load without any appreciable displacement of the wheel carrying frames I2. Thus, when the cleaner is not operating, its forward portion is supported almost entirely by the trailing wheels II, Il, which penetrate the carpet nap until the leading wheels face, as shown in Figure 4.

Now. upon starting the the suction exerted at the nome constitutes an additional loadtending to depress the front portion of the cleaner and due to the factthat the leading wheelFIl, ll have relatively shortlever arms; they act to support the suction load, sinking into the carpet until the resistance to' penetration overcomes the tension of the springs I5, and the wheel supporting frames I2 adjust their positions to raise or lower the nozzle. In short. it may be assumed that the trailing wheels Il, Il supportthe more or less constant static load, and that the leading wheels Il, Il carry the suction load and as a result the height of the nozzle is determined by the relative positions of the two pairs of wheels and is not dependent upon the depth of penetration of a single pair of wheels into the carpet.

And finally, in connection with the herein disclosed types of tandem wheel nozzle height adjustments, the width of the leading and trailing wheels may be varied in order to obtain any desired ratio of penetration of their tread surfaces into the carpet nap and thereby secure a more accurate and sensitive adjustment with l cleaner m operation,

less pronounced. variations in carpet characteristics.

Having set forth a preferred and modified embodiment of the invention, I claim:

1. In a suction cleaner, the combination of a casing having a nozzle at its forward end, ilxed supporting wheels at the rear end of said casing, front wheel carrying members pivotally mounted on opposite sides of said casingeadjacentisad nozzle for limited rocking movement about an axis transverse to the direction of movement of said cleaner, pairs of wheels arranged in tandem and journalled on said wheel carrying members, the distance to the foremost wheelbearing such relation to the distance of the rearmOSt'heel from the pivot point of each wheel carrying member asv to throw the greater portion of the load on one pair of wheels leaving the other comparatively free to ride upon the surface of the carpet and to adjust the angle of the wheel supporting member Sumciently to maintain said nozzle at a substantially uniform height above the carpet surface.

2. In a suction cleaner, the combination of a casing having a nozzle at its forward end, fixed and adjustable supporting wheels at opposite ends of said casing, said adjustable wheels being arranged in tandem at the forward end of said casing and journalled at opposite ends of supporting members consisting of horizontally extending bars pivotally mounted intermediate their ends on said casing, the pivot point of each bar being disposed relatively nearer the trailing adjustable wheels, thereby allowing the leading adjustable wheels to ride relatively freely on the surface of the carpet and control the vertical displacement of the trailing adjustable wheels in accordance with the angular adjustment of said bars.

3. In a suction cleaner, the combination of a casing having a nozzle at its forward end, front and rear support-ing wheels, the front wheels consisting of two pairs arranged in tandem on opposite sides of said casing adjacent said nozzle, and means for adjustably supporting said pairs of front wheels, comprising bars having free pivotal mounting on said casing with one pair of wheels journalled at opposite'ends of each bar, the pivot" points of said bars located relatively nearer the trailing wheels, whereby the latter support the greater part of the load and leaving the leading wheels free to control the angular displacement of said bars in proportion to the depth of penetration of the carpet nap by said trailing wheels.

4. In a suction cleaner, the combination of a casing having a nozzle at its forward end, front and rear supporting wheels, the front wheels consisting of two pairs arranged in tandem on opposite sides of said casing adjacent said nozzle, and means for adjustably supporting said pairs of adjustable wheels, comprising bars having free pivotal mounting on said casing intermediate their ends with one of each pair of wheels journaued at their ends, and their pivot points sufnj nap by said trailing wheels.

5. In a suction cleaner, the combination of a casing having a nozzle extending transversely of its forward end, front and rear supporting wheels, the front wheels consisting of pairs positioned adjacent said nozzle, and means for adjustably` supporting said pairs of front wheels comprising bars having free pivotal mounting on said casing intermediate their ends and extending longitudinally thereof, one of each pair of said wheels being journalled at the ends of each bar in tandem arrangement with the pivot point relatively nearer one of said wheels whereby the same serves as the load supporting wheel leaving the other ree to ride upon the carpet surface and control the vertical displacement of the nozzle and to compensate for the varying thickness and quality of the carpets being cleaned in the manner described.

6. In a suction cleaner, the combination of a casing having a nozzle at its forward end, front and rear supporting wheels, the front wheels consisting of two pairs arranged in tandem and journalled on supporting members comprising bars pivotally mounted on opposite sides of' said cleaner -adjacent said nozzle, with said pairs of wheels journalled at diierent distances from the pivotal axes of said bars, whereby the pair of wheels nearest thereto carry the greater part of the load leaving the other pair of wheels comparatively free to ride in contact with the carpet surface and control the vertical displacement of the nozzle by the angul-ar position of said bars, and compression springs located between said bars and said casing and acting to assume a predetermined portion of the load thereon.

7.- In a suction cleaner, the combination of a casing having a nozzle extendingtransversely of its forward end, front and rear supporting wheels, the front wheels consisting of pairs arranged in tandem vadjacent Asaid nozzle, bars pivotally mounted on said casing at their forward ends and extending-rearwardly therefrom, one of each pair of said front wheels being journalled on each of said bars, with the pair mounted relatively nearer the pivot points of said bars serving to support a greater portion of the load and leaving the other pair free to ride upon the carpet surface. vto adjust the position of said bars to the thickness and quality of the carpet being cleaned and compression springs introduced between the free ends of said bars and the casing.

CHARLES H. TAYLOR. 

